Interaction between wide area cellular networks and wireless local area networks is currently handled by elements of the packet core network using higher layer protocols and procedures. For example, the elements of the packet core network may be the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) S1 and S2 interfaces. For example, the LTE S1 interface is described in the 3GPP Technical Specification (TS) 36.413, “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP)”, v.11.3.0, Mar. 18, 2013. The LTE S2 interface is described in 3GPP TS 23.402, “Architecture enhancements for non-3GPP accesses”, v.12.0.0, Mar. 8, 2013. The contents of both of TS 36.413 and TS 23.402 are incorporated herein by reference. Such access is beyond the scope of the radio access infrastructure in either of the WLAN or cellular networks.
Typically, communication between base stations and a cellular network involve signalling sent through backhaul facilities of the network infrastructure. Such interaction may be performed directly between base stations, for example through an LTE X2 interface, or may be performed indirectly via elements of the packet core network such as the LTE S1 interface. However, significant delays may be inherent in these interactions due to the physical topology of the network infrastructure, which may provide some impediment when trying to achieve tighter cooperation between the LTE macro cells and small cells, and for seamless mobility. One example of such a small cell is an Institute for Electrical and Electronics Engineers (IEEE) 802.11 network, commonly known as “WiFi”. Such a network is, for example, described in IEEE 802.11-2012, “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications”, March 2012, the contents of which are incorporated herein by reference.
Current solutions for interworking between the 3GPP cellular networks and 802.11 WLANs rely on the UE to make decisions regarding whether to attempt a network connection through a WLAN access point. After the UE has made such a decision, a network access via the WLAN is based on the evolved packet core (EPC) procedures rather than on the radio access network (RAN) procedures. As a consequence, a cellular network has little control over how, when or where the UE chooses to associate with the network, making it difficult to manage the use of the 802.11 small cells for traffic offload and to provide seamless mobility between LTE or other network technologies and the 802.11 or other similar technologies.